I recently got the Maximus Gene III and assembled a system. When I first booted up I thought the system failed since I did not hear any beeping sound indicating POST but was able to go into BIOS. I was wondering if this is normal that the mobo has no onboard bios speaker?

Yeah, I'm noticing more and more that manufacturers seem to be offering small speaker 'dongels' that you can plug in to the board. This allows you to choose whether you want MB sound or not. Personally, I find it reassuring to have the MB post beep code tell me everything is OK...

The majority of motherboards don't have onboard speakers, and that was never a common practice. The only thing that changed is that most case manufacturers also stopped putting speakers in their cases. Now they usually include a stand-alone speaker inside one of the accessory bags.

The front-panel header on the motherboard where you attach the LEDs and switches is where the speaker connection is located. Since this is an ASUS motherboard, it should have come with a Q-connector that has the connection for the speaker marked on it.